Zukertort Opening: Black Mustang Defense: what should White play?

In the Zukertort Opening: Black Mustang Defense (ECO A04), White's most effective continuation is d4, seizing central space and preparing standard Queen's Pawn structures. With an engine evaluation of +0.48, d4 is the most frequent choice in the position, played in 41.0% of the 13,208,905 recorded games and yielding a 56.2% score for White.

Central control with d4

By playing d4, White stakes an immediate claim in the center while preventing Black's c6 from supporting an easy central advance. The move establishes a solid foundation that often transitions directly into standard Queen's Gambit or classical Queen's Pawn setups. An illustrative continuation demonstrating this central development is d4 d5 c4 e6 Nc3 Nf6, where White secures comfortable development and space.

Alternative central transpositions

White can also transpose directly into double king's pawn setups using e4, which appears in 15.7% of games (2.08M recorded) with a +0.20 evaluation and a 50.9% score. This option frequently transitions into Open Game structures, as seen in the illustrative line e4 e5 Bb5 Nf6 O-O Nxe4. Another classical path is Nc3, chosen in 7.7% of games with a +0.04 evaluation and a 48.9% score, exemplified by Nc3 d5 d4 Bf5 e3 e6.

Hypermodern setups

White also retains flexible flank options that avoid committing the central pawns immediately. The fianchetto move g3 is the second most common try, played in 25.4% of games (3.36M recorded) with a +0.13 evaluation, illustrated by the continuation g3 e5 c4 Nf6 Bg2 d5. Alternatively, the English-style c4 scores 54.1% across 10.1% of games (+0.11 evaluation), following paths such as c4 e5 g3 e4 Nh4 Nf6.